The present application relates generally to an improved data processing apparatus and method and more specifically to mechanisms for hybrid backup and restore of a very large file system using metadata image backup and traditional backup.
A file system is a software component that manages a defined set of storage devices and provides access to data in ways to facilitate consistent addition, modification, and deletion of data and data files. The term is also used to describe the set of data and metadata contained within a specific set of storage devices. A file is a named string of bits that can be accessed by a computer application. A file has certain standard attributes, such as length, modification time, and time of last access. Metadata is data providing information about one or more aspects of data, such as time and date of creation, creator, or author, storage location, and the like.
The advent of storage area network (SAN) file systems and low cost storage have created the possibility of very large file systems with a very large number of files. Unfortunately, the time required to completely restore file systems from a backup copy is proportional to the file system size. The customer has the choice of manually restoring files of particular interest first and allowing access to the file system with only an incomplete set of data restored, or delaying access until all data have been restored, The first option requires the administrator to precisely identify the data to be accessed, because applications that access unrestored data would fail. The second option involves the delay of resumption of business until all of the files have been restored.